Synthesis and characterization of hydroxyapatite/titania nanocomposites using in situ precipitation technique Mahnaz Enayati-Jazi a,⇑ , Mehran Solati-Hashjin b , Ali Nemati a , Farhad Bakhshi b a Department of Materials Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran b Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran article info Article history: Received 20 November 2011 Received in revised form 25 January 2012 Accepted 10 February 2012 Available online 20 February 2012 Keywords: Hydroxyapatite (HAp) Titania (TiO 2 ) Nanocomposites In situ precipitation abstract Hydroxyapatite/titania nanocomposites were successfully synthe- sized by in situ precipitation of precursor matters from hydroxyap- atite and titania at 70 °C with different hydroxyapatite/titania ratios. X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface, scanning and transmission elec- tron microscopes were employed to characterize the prepared nanocomposite powders. X-ray diffraction results indicated that hydroxyapatite and anatase (TiO 2 ) were the major crystalline phases. By increasing the amount of titania nano-particles, Fourier transform infrared spectroscopy revealed that (PO 4 ) 3 bands at 567, 1033 cm 1 decreased. Brunauer–Emmett–Teller surface results also showed a reduction in surface areas of nanocomposites. Transmission electron microscope observations revealed that the aspect ratio of hydroxyapatite/TiO 2 nanocrystals increased by increasing TiO 2 proportion in nanocomposites. The observed nano- rod crystals tended to thin, elongated and plate-like in shape. Ó 2012 Published by Elsevier Ltd. 1. Introduction Hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ), abbreviated as ‘‘HAp’’ is one of the most attractive ceramic materials for vertebrate and dental implant applications due to their compositional and biological similarity to native hard tissues [1–3]. HAp is the main mineral constituent of teeth and bones. According to the literature, HAp ceramics do not exhibit any cytoxic effects. Moreover, HAp can directly bond to biocompatibility with hard tissues and also with the bone [4]. However, because of 0749-6036/$ - see front matter Ó 2012 Published by Elsevier Ltd. doi:10.1016/j.spmi.2012.02.013 ⇑ Corresponding author. Tel.: +98 021 44865100; fax: +98 021 44865105. E-mail address: Mahnazenayati@yahoo.com (M. Enayati-Jazi). Superlattices and Microstructures 51 (2012) 877–885 Contents lists available at SciVerse ScienceDirect Superlattices and Microstructures journal homepage: www.elsevier.com/locate/superlattices